Russia was the first country to authorize a COVID-19 vaccine, but it did so before completing proper scientific studies to show it is safe and effective.
Now, with questions about Russia's vaccine swirling, experts interviewed by ABC News expressed concern about the country's swift action to disseminate the unproven vaccine to low and middle-income countries, noting that if the vaccine were to prove a failure, it could fuel vaccine skepticism globally.
Russian scientists from the Gamaleya National Research Center published their findings of an early-stage study in the prestigious medical journal, The Lancet, on Sept. 4, showing that the vaccine was safe.
But molecular biologist Dr. Enrico Bucci said he quickly developed "several concerns" upon looking at the data. Bucci, who heads a science integrity company called Resis, in Italy, published an open letter on his blog about Russian's vaccine study. The letter quickly gained additional signatories, and on Sept. 7, the scientists submitted their formal complaint to The Lancet.
The letter highlighted data irregularities in the study that appear to be duplicated. It has now been signed by a total of 38 experts.
"We do not allege misconduct, we just want them to provide additional data," said Dr. Konstantin Andreev, one of the signatories and a microbiologist and biophysicist affiliated with the Howard Hughes Medical Institute and Northwestern University.
Another researcher who signed the open letter, Dr. Donald Thea, the director of the Center for Global Health & Development at the Boston University School of Public Health, said, "What we need to see is the data. Science is based on transparency and accuracy and precision -- even more when it comes to a global vaccine effort of such huge proportions and importance."
The Gamaleya National Research Center for Epidemiology and Microbiology did not respond to ABC News' request for comment.
Sputnik V has also not completed the large Phase 3 randomized control trials that are required in the United States and many other countries prior to vaccine approval. These studies traditionally compare the vaccine to a placebo in thousands of people to determine whether it works in preventing disease, and to further assess its safety profile.
"The thing is that they try to start distributing the vaccine even before completing Phase 3 clinical trials, and the Phase 1 and Phase 2 trials described contain only a very, very small number of patients, only 76 patients, [an] enormously small [amount] for such an important topic," said Andreev. Russia was able to initially skip the Phase 3 clinical trials due to differences in international regulatory agencies.
As Russia prepares mass production of Sputnik V, there are significant global health implications to be considered. Although international scientists have warned that no one truly knows yet if the vaccine works, Russia is already accepting purchase orders from low and middle-income countries eager to obtain a coronavirus vaccine.
In a recent article in The Lancet, Kirill Dmitreiv, CEO of the Russian Direct Investment Fund, confirmed that Russia has received international requests for 1 billion doses of its vaccine.
Russia is talking to at least 20 countries about exporting the vaccine, including Brazil, Cuba, the Philippines and Saudi Arabia. If the vaccine is given to people before it's properly tested, however, the consequences could be catastrophic.
"If what we end up with is people in poor countries getting untested vaccines, first of all, ethically, that's a disaster," said Dr. Ashish Jha, the dean of Brown University's School of Public Health.
"Second, it will have very long implications for the health of those people and their confidence in vaccines. So, I think it's critically important that we don't do this anywhere, but particularly we don't do it in low-income countries."
Other experts cautioned that the global distribution of an ineffective vaccine could promote vaccine hesitancy and create a false sense of security that could further propagate COVID-19 transmission.
"I'm hopeful that it will work, but if it doesn't, it will send huge mixed signals to the global community," Jha said. "People will be very, very hesitant to take the COVID vaccine," he said, if the Russian vaccine ends up not working.
"If we are lucky, it will be, you know 70-80% effective," Jha said.
"They are going to think they are protected and they very well might get sick and then die from it," he added. "So, it is absolutely essential to figure out how effective it is and then communicate that to people. But the problem is, if you haven't tested it, you don't know how effective it is. And if you don't know how effective it is, you don't know what to tell people, and you're going to create this huge false sense of confidence that could be very, very dangerous."
Alexandra Lambert, D.O., MPH, is a chief resident in emergency medicine at VCU Health, and a contributor to the ABC News Medical Unit.